Jodster,
I've been wearing hearing aids for 20 years and can tell you that yes, it is an ongoing process that gets better over time. Some people are lucky enough to benefit from their aids immediately while others must work awhile to find hearing aids, program settings and/or earmolds that help them hear best.
One of the most important things you can do to ensure good hearing aid programming/adjustment is to communicate with your audi by telling him/her what you're hearing with your aids. (i.e. what you like/don't like about the sound of your aids -- Do sounds cut in and out? Are they uncomfortably loud? When you talk, does your voice sound like it's in a barrel? Do you hear feedback (squealing) when you turn the volume control on your aids too high? etc.) Unless you communicate these things to your audi, there is no way he/she can make the necessary changes in order to provide you with the best hearing possible.
Second: Ask questions! If there is something you don't understand (your audiogram, hearing aid features, terminology/vocabulary, etc.), ask your audiologist to explain it to you. When I started wearing hearing aids at the age of 15 for a moderately-severe hearing loss, I asked my audiologist to mail a short letter to me (e-mail wasn't available at this time) which explained my hearing loss in laymen's terms. This allowed me to better understand my loss so that I could explain it to others. Audiologists (most of them, anyways) are more than happy to answer any questions you have about hearing loss and hearing aids. Remember, the best hearing aid consumer is an educated consumer.
Speaking from my own experience: Several years ago I received digital hearing aids (Oticon DigiFocus II super power BTEs) and had to return to my audi several times because I wasn't happy with their sound quality. I have a severe-profound hearing loss and for whatever reason voices and environmental sounds just didn't come through as clearly as they did with analog aids. At this time I also received soft earmolds that were painful to wear. After speaking with my audiologist about these issues, I switched to hard shell Lucite earmolds (which I've always used). From that point on I no longer had any difficulty wearing the aids for extended periods of time. Unfortunately I couldn't get my aids programmed to provide enough clarity and amplification, so I stopped wearing them and went back to my trusty analogs. Interestingly enough, I now have a CI and my audi was able to tweak my digital aid so that it compliments what I hear through my implant. (I have a CI in my left ear and wear a digital hearing in the right ear.) I'm now very happy my digital aid and how it supplements what I hear with my CI.
I hope I didn't come off too preachy here.
That wasn't my intent, but I do hope this information was helpful!! <smile>
The Lucite earmold I wear now is so comfortable I don't even know I have it on 99% of the time. I have small ear canals which make inserting and removing soft earmolds very painful. Ouch! 